JP5724964B2 - Suction casing of water jet propulsion device - Google Patents

Description

  The present invention relates to a water jet propulsion device that has a suction casing that sucks water from a suction port that opens at the rear bottom of a ship, and that receives thrust of a pump part by the suction casing. The present invention relates to a water jet propulsion device that disperses stress on a plate.

Conventionally, a suction casing of a water jet propulsion device is composed of a cylindrical water absorption part through which flowing water passes and an attachment part attached to the ship bottom and transom of the ship. The water absorption part is inclined upward from the ship bottom toward the transom. doing. A bearing box having a bearing inside is attached to the bow side of the inclined surface of the water absorbing portion, and a main shaft that engages the impeller is pivotally supported.
A boat equipped with a small or medium-sized water jet propulsion device cannot be made up of the space occupied by the water jet propulsion device in the engine room, so it is composed of a suction casing with a bearing box having a thrust bearing as described above. ing. Such a structure is well known as disclosed in Patent Document 1.

JP 2001-122191 A (FIG. 2)

In conventional water jet propulsion devices, many aluminum castings or aluminum alloys are used as the structural material of the suction casing. The cylindrical water-absorbing part forming the flow path and the plate-like attachment part attached to the ship and the transom are formed as an integral structure by a mold, a sand mold, welding or the like. If a bearing housing is attached to the inclined surface of the water absorbing part, a large load is applied to the connecting member (flange) with the bearing housing, stress concentration occurs at the connecting member or the joint between the connecting member and the inclined surface of the water absorbing part, and deformation / breakage occurs. There is a fear. In addition, stress concentration occurs at the joint between the cylindrical water absorbing portion and the plate-like mounting portion, and there is a risk of deformation and damage in the same manner.
The present invention relates to a suction casing that receives thrust generated by a water jet propulsion device, by providing reinforcing ribs at places where stress is concentrated, and distributing stress to the flow path of the suction casing or the mounting plate to the ship, A suction casing for a water jet propulsion device capable of increasing fatigue strength is provided.

A bearing flange for coupling the shaft receiving box secured to the inclined channel, when extending from the bearing flange ends lateral vertical ribs to the bottom mounting plate, a strength member to bending moments to the fore side of the bearing flange suction A load can be received in the flow path.

  In addition, when a bow-side rib is erected at the bow-side joint between the bottom mounting plate and the inclined channel and continuously extends to the vicinity of the center of both ends of the inclined channel, the joint between the inclined channel and the bottom mounting plate is obtained. Strength is increased and it has strength against torsion and bending of the ship bottom.

In the suction casing of the water jet propulsion apparatus according to the present invention, the axial thrust is axially supported by the bearing box, and the stress generated thereby is distributed to the strength member, so that stress concentration can be reduced. Moreover, since the section modulus for receiving stress on the suction casing due to torsion or bending of the boat can be increased by the rib, the thickness of the main part can be reduced, contributing to weight reduction.

It is a side view of a ship equipped with a water jet propulsion device according to the present invention. Similarly, it is a longitudinal cross-sectional view of a water jet propulsion device. Similarly, it is the oblique view which looked at the suction casing of the water jet propulsion apparatus from the transom side. Similarly, it is the oblique view which looked at the suction casing of the water-jet propulsion apparatus from the drive part.

FIG. 1 is a side view of a boat equipped with a water jet propulsion device according to the present invention. The water jet propulsion device W is a water absorption portion that sucks water from a suction port S2 that opens in a rear bottom S1 of the boat S. W1, a pump unit W2 that pressurizes sucked water and discharges it behind the stern transom S3, and a steering unit W3 that controls the injection direction of the discharged jet to steer the boat S. The water jet propulsion device W is connected to a drive unit E provided in the engine room S4.

The ship bottom S1 and the transom S3 of the boat S are connected to the water jet propulsion device W, and the boat S is propelled forward in response to the reaction force of the jet discharged from the water jet propulsion device W.

FIG. 2 is a longitudinal sectional view of the water jet propulsion device, in which water sucked from the water suction port 2 of the suction casing 1 communicating with the suction port S2 of the ship bottom S1 is pressurized by the impeller 3 of the pump unit W2 and discharged. The watercraft S is propelled by injecting pressurized water from the injection nozzle 5 to the rear of the stern. The jet water is jetted to the left and right by rotating with the deflector 6 for changing the traveling direction. The deflector 6 is rotated from the ship by the operation rod 7. Moreover, the watercraft S is moved backward by changing the direction of the jet water with the reverse reverser 8 and injecting the water in the direction of the watercraft. When moving forward, the reverser 8 is rotated upward so that the jet does not come into contact with the reverser 8.

The drive part E of the engine room S4 is connected to a main shaft 9 extending through the suction casing 1 of the water jet propulsion device W, and is fitted to the main shaft 9 by a pump unit W2 via the main shaft 9. The impeller 3 is rotated. The thrust in the bow direction generated from the impeller 3 is pivotally supported by a bearing box 10 attached to the suction casing 1 and transmitted to the boat S through the suction casing 1.

The water jet propulsion device W jets pressurized water into the air behind the stern. Therefore, the water absorption part W1 of the suction casing 1 forms the inclined flow path 11 diagonally upward toward the transom S3 from the suction port S2 opened to the ship bottom S1. In the vicinity of the transom S3, a cylindrical shape which is substantially horizontal to the ship bottom S1, and a rotatable impeller 3 is inserted inside. The main shaft 9 fitted to the impeller 3 extends to the bow side, and is supported by a bearing box 10 attached to the inclined flow path 11 of the suction casing 1. The bearing box 10 is connected to a bearing flange 12 formed above the inclined flow path 11 of the suction casing 1.

3 is an oblique view of the suction casing of the water jet propulsion device as seen from the transom side, and FIG. 4 is an oblique view of the suction casing of the water jet propulsion device as seen from the bow side.
The water jet propulsion device W receives torsion and bending stress from the bottom S1 and the transom S3 due to the deformation of the boat S. At the same time, the bearing box 10 receives the thrust generated by the water jet propulsion device W.

  The thrust in the bow direction generated in the impeller 3 of the water jet propulsion device W is pivotally supported by a bearing box 10 attached to the suction casing 1 and transmitted from the suction casing 1 to the boat S via the bearing flange 12. The The suction casing 1 is fixed to the ship bottom S1 and the transom S3, and a force that pulls the inclined flow path 11 of the suction casing 1 to the bow side acts. Stress concentration occurs in the joint portion that attaches the suction casing 1 to the bearing flange 12, the ship bottom S1, and the transom S3. For this reason, the suction casing 1 that transmits the thrust in the bow direction to the boat is provided with reinforcing ribs 14, 15, 16, and 17 at various points.

Above the inclined flow path 11 of the suction casing 1, a bearing flange 12 connected to the bearing box 10 protrudes substantially vertically from the ship bottom S1.
Horizontal ribs 14 are provided from the center of both ends of the bearing flange 12 toward the transom S3, and are fixed to the suction casing 1 while increasing the width of both ends. The horizontal rib 14 is substantially parallel to the ship bottom S1. In the embodiment, it extends to substantially the center line of the inclined channel 11.

Since the thrust in the bow direction generated in the impeller 3 is supported by the bearing box 10, the bearing flange 12 connected to the bearing box 10 is pulled in the bow direction. Although stress concentration occurs at the joint between the bearing flange 12 and the suction casing 1, the stress is distributed to the substantially horizontal cylindrical pump portion W2 of the suction casing 1 by the horizontal ribs 14 extending from both ends of the bearing flange 12. The damage of the joint portion of the bearing flange 12 can be prevented.

Vertical ribs 15 are provided on both sides of the bearing flange 12 projecting from the inclined flow path 11 of the suction casing 1. The bearing flange 12 is fixed to the bottom mounting plate 18 via the inclined flow path 11 of the suction casing 1 while increasing the width from the vicinity of the center of the bearing flange 12 to the side.

The thrust in the bow direction generated in the bearing flange 12 disperses stress in the inclined flow path 11 of the suction casing 1 by the vertical ribs 15 suspended from both ends of the bearing flange 12, so that damage to the joint portion of the bearing flange 12 can be prevented.

On the bow side of the suction casing 1, a bow side rib 16 is provided at a joint portion between the bottom mounting plate 18 and the inclined flow path 11. The bow-side rib 16 is continuously provided from the bow-side joint portion of the bottom mounting plate 18 and the inclined channel 11 to both ends of the inclined channel 11, and extends to the vicinity of the center of the inclined channel 11. The bow-side rib 16 is erected at a certain height. In order to avoid stress concentration between the inclined channel 11 and the bow-side rib 16 in the vicinity of the central portion of the inclined channel 11, the height of the bow-side rib 16 is not provided.
The suction casing 1 of the present embodiment has a projection 19 for attaching a screen below the inclined channel 11, and the convex 19 has a width to both ends of the inclined channel 11. Both end side walls are continuously connected to the bow-side rib 16.

The stress applied to the suction casing 1 due to the torsion or bending of the boat is distributed to both ends of the inclined flow path 11 of the suction casing 1 by the bow-side ribs 16 provided on the bottom mounting plate 18. Breakage of the joint portion of the inclined channel 11 can be prevented.

On the stern side of the suction casing 1, a stern side rib 17 that connects the bottom mounting plate 18 and the inclined flow path 11 is provided. The inclined flow path 11 and the bottom mounting plate 18 are suspended from the bottom of the inclined flow path 11 to the bottom mounting plate 18 to form a substantially triangular stern side rib 17.
In this embodiment, the stern-side ribs 17 are suspended from the lower ends of both ends of the inclined channel 11 and are continuously provided up to the transom mounting plate 20 while standing on the bottom mounting plate 18 at a certain height. The transom mounting plate 20 is also erected at a certain height and connected to both ends of the upper cylindrical pump portion W2. The bottom mounting plate 18, the transom mounting plate 20, and both ends of the pump unit W <b> 2 are continuously connected by the stern side ribs 17 from the lower ends of both ends of the inclined channel 11.

The stress applied to the suction casing 1 due to the torsion or bending of the boat is distributed to both ends of the inclined flow path 11 of the suction casing 1 by the stern ribs 17 provided on the bottom mounting plate 18 and the transom mounting plate 20. It is possible to prevent damage to the joint portion of the bottom mounting plate 18, the transom mounting plate 20, and the inclined flow path 11.

  The suction casing of the water jet propulsion apparatus according to the present invention can disperse the stress to strength members such as a flow path of the suction casing or a mounting plate to the boat by applying reinforcing ribs to portions where stress concentration is applied. Therefore, the fatigue strength of the member is increased, the thickness and weight can be reduced, and the life can be extended. This is useful for a small or medium-sized water jet propulsion device that receives thrust by a bearing box attached to the suction casing.

DESCRIPTION OF SYMBOLS 1 Suction casing 3 Impeller 9 Main shaft 10 Bearing box 11 Inclined flow path 12 Bearing flange 14 Horizontal rib 15 Vertical rib 16 Bow side rib 17 Stern side rib 18 Bottom mounting plate 20 Transom mounting plate S3 Transom W Water jet propulsion device

Claims (2)

In the water jet propulsion device (W) in which the main shaft (9) of the impeller (3) passes through the inclined flow path (11) and is supported by a bearing box (10) attached to the suction casing (1).
The bearing flange (12) connecting the bearing box (10) is fixed to the inclined flow path (11), and the vertical rib (15) is extended from the both sides of the bearing flange (12) to the bottom mounting plate (18). A suction casing of a water jet propulsion device. In the water jet propulsion device (W) in which the main shaft (9) of the impeller (3) passes through the inclined flow path (11) and is supported by a bearing box (10) attached to the suction casing (1).
A bow-side rib (16) is erected at the bow-side joint between the bottom mounting plate (18) and the inclined channel (11), and is continuously extended to the vicinity of the center of both ends of the inclined channel (11). A suction casing of a water jet propulsion device.

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